Fire-extinguishing plant



Jan. 1o, 192s. 1,655,722

lH. E. BEDFORD FIRE EXTINGUI SHING PLANT Filed June 10, 1925 3 Sheets-Shed'I 1 Jam 10 1928n 1,655,722 H. E. BEDFORD FIRE EXTINGUISHING PLANT Filed June 10. 1925 5 Sheets-$heet 2 Ak. Fig zj BY l W jo

Jan. 10, 1928. 1,655,722

H. E. BEDFORD FIRE EXTIHGUISHING lLANT Filed June 10. 1925 3 Sheets-Sheet 3 FWG.

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Patented Jan. l0, 1928.4

UNiTEDfsTATEs 4iii'rsia'r o FFicE. y

HOWARD EDWIN BEDFORD, oF LoNDoN, ENGLAND, AssIGNoB., BY N'EsNE AssIGN- MEN'rs, 'ro PYRENE immmx conronA'rIoN, or Niiwaax, Ntiw .masa-z, A conro- BA'IION'l 0F DELAWARE.

FIRE-EXTINGUISHING PLAN T.

Application led June 10, 1925, Serial No.

This invention relates to fire extinguishing apparatus of the class wherein an acid solution and an alkaline. solution in conjunction with a foam producing agent produce a foam 5 jet which is ejected through a nozzle. The object of the present invention is to enable steam ejeetors to ibe employed for propelling the two solutions to the nozzle in such' a way that the latter can ie sluit off for manoeuvring purposes, for example, on board ship, without breaking or interrupting the thread of the steam ejeetois.

With this aim in view according to the present invention the two solutions are drawn from their respective tanks each by means of a steam ejector and forced into the respective pipe mains by means of which the solutions are carried to the foam nozzle; the

pi es through which the solutions are taken ofip from the tanks are each provided with a check valve anda by-pass "tube of relatively small bore is furnished from thev delivery side of each ejector nozzle -and delivers into the upper part` of the respective solution tanks. y this means when the nozzle is sluit down with the steam on, any surplus solution 4sucked througlifis returned to the upper part of the respective tank; the by-pass in each case is only of sufficient cross-section to prevent an interruption or break inthe jet of the ejector. In order that the invention may be clearly understood and may be rcadilycarried into practice, an installation constructed in accordance therewith will now be described more fully with reference to the accompanying drawings, wherein Figure 1 is a front elevation of the solu-ly tion tanks and their fittings showing the tank 40 for the acid solution in section;

Figure 2 'is an elevation from the righthand side of Figure 1; j Figure 3 is a plan of Figure 1;

Figure 4 is a horizontal central section showingr the stop valve with its hand wheel removed;

Figure 5 is a central vertical section through one of the two check valves fitted in the two steam branches;

Figure 6 is an. elevation from the delivery end of one ofthe steam ejeetors or jet pumps, to wit, the ejector shownr at the left in Figure 3;

36,276, and in Great Britain limeA 14, 1924.

Figure 7 is a vertical section of the same on the line VII- VII in Figure 6;

. '.Figure 8 1s 'a central horizontal section of Figure 6, and finally i l Figure 9 is a central vertical section through one of the check valves located in the ofitake pipes from `the solution tanks.

Referring first to the general arrangement shown in Figures 1 to 3, the system 1s arranged to employ two effective solutions, for example, an acid solution of aluminumsulphate and an alkaline solution of sodium bicarbonate, the latter also containing the foam producing agent, such as licorice or logwood extract. These solutions' are contained in two tanks 1,2 which are made D-shape in plan or horizontal'scction and are placed back to back as seen in Figure 3 in order to econon'ilze space. The acid tank 1 is shown provided with a lead lining 3 to resist corrosion. These tanks do not need to be of such careful manufacture with the joints as carefully tested as was essential in previous systemsV wherein the liquid in the tanks was ejected L by means of steam pressure admitted to the Y tanks.

The steam supply pipe 4' is brought down linto a' position just above the .dividing wall or partition between the tanks l and 2 and has two branches 5, 6 each of which passes over the top of one of the tanks l, 2 and the steam supply pipe 4 is furnished with a regulating valve 7 at its junction with the two branches 5, 6. It is essential that this steam'regulating-'valve shall be capable of very fine regulation at the moment of opening, although such fine regulation is not so necessary when it is well open. The details of a suitable valve 'generally of known form for use in this connection are shown in Figure 4. The valve itself is in the form of a tubular plunger or petticoat 8 fitting within the bore of the seating 9 and the plunger has cont-rol ports 10 of triangular shape so that on the first opening of the valve the steam from the pipe 4 escapes into the branches 5 and 6, gradually through the apex of the triangular port 10 so that the regulation at the moment of opening is a fine regulation, but a more rapid increase in opening'is obtained when the valve is fairly fully open. An .alternative arrangement which will produce a similar effect and is satisfactory for the present purpose, although rather more coinplicated, is a stop valve provided with a differential screw stein to allow of fine adjustment, but the arrangement illustrated is preferred on account of its simplicity.

The steam supply tothe pipe 4 may be normally at a pressure from 4;() to 60 pounds per square inch, or even as high as pounds per square inch, but the installation is capable of being worked with a steam pressure as low as 30 pounds per square inch. Each of the branches' 5 and 6 ot' the steam pipe is furnished with a check or non-return steam valve 11 so that should the steam pressure entirely fail suddenly, there is no risk of acid or alkaline liquid flowing back through the stop valve 7 into the steam pipe 4. Details of the check valves 1-1 are illustrated in Figure 5 wherein the normal direction of flow of steam is indicated by the arrows. The valve proper closes normally due to its own weight and is raised and opened by the steam pressure, but any tendency to backward flow is prevented by immediate closing of the valve automatically. The branches 5, 6 of the steam pipe after leaving the check valves 11 are each turned downwardly and then rearwardly and immediately after turning rearwardly eacli has inserted in its length a steam ejectoror jet pump 12, which although of quite usual con-- struction is illustrated in greater detail in Figures 6 to 8. These ejectors serve to set ,up afsuction in the annular space around their nozzles 13. Each of the ejectors 12 is connected to a hollow fitting 14 which serves to connect the annular suction space around the respective nozzles 13 with an olf-take pipe 15 best seen in Figure 1. The lower ends of the pipes 15 are perforated and terminate in small wells 26 in the bottom of the tanks 1, 2 arranged so that the whole of the liquid in each tank can be substantially drawn up through the pipes I5. The purpose of the steam jets 13 is therefore to create a suction in the two off-take pipes 15 so that the two solutions are respectively drawn up from the tanks 1, 2 into the steam pipes 5, 6, to the outlet ends of which are connected liquid supply-.mains 5 and 6. These supply mains 5 and 6 are united, as shown at 30, and are connected with a suitable mixing nozzle 31 which is provided with a control valve 32.` When the nozzle 31 is open and in operation, there is a continuous flow of steam through each of the ejector nozzles 13 thus producing a continuous flow of the acid and alkaline solutionsin the two pipes 5, 6 and a continuous production of foam in the nozzle 31 to be projected therefrom in a stream on to the lire which it is desired to extinguish.

. In practical use, particularl ship, it is necessary to shut off t e nozzle 31 occasionally while the operator manuvres on boardl valve 7 and in order to make it possible to shut oif the nozzle 31 without forcing the steam passingl through the valve 7 downwards by way of the olf-take pipes 15 into the solution tanks l, 2, a check valve or nonreturn valve 16, shown in Figure 9, is located in each of the littings la so as to shut automatically when the suction ceases and steam pressure is set up above the valves 16. Each of the check valves 16 is of similar construction to the valve 11 shown in Figure 5, normally closing by its own weight but in operation drawn up and opened by the suction created by the nozzles l5. If the steam were allowed to pass through the ott-take pipes 15 into the tanks l, 2 when the nozzle 31 was shut oli', not only would the solution in each tank be overheated but all the pipes in the neighbourhood would be warmed up and would make it dillieult to start the jets afresh after an interval and such restarting would not be sulliciently rapid. ln order to prevent the jet breaking when the nozzle 3l is snut olf. a by-pass of small cross-section is employed to connect the delivery side of each of the ejectors 12 to the upper part of the respective solution tank. ln the form illustrated, this by-pass consists oi a small port or passagei 19 cast in the end flange 2U of each of the ejectors l2, the flange 2t) in each case being cast with a foot 2l by means of 1-v which each ejector is secured to the top of the respective tank l or 2. rlhe by-pass passages 19 are of small cross-section, in fact the cross-section of each is only just suliicient to prevent the jet breaking when the nozzle 31 is shut ott'. Any surplus solution sucked through the olf-take pipe 15 when the nozzle 3l is shut olf with the steam pressure turned on is returned to the upper part of the tank in uestion through the bypass passage 19. T iis arrangement has the further advantage that it sets np a wei-tain amount of stirring or agitation of the solutions in the two tanks because the solution lay-passed is taken from the lower part of the tank by the olf-take pipe 15 and is returned to the upper part through the passage 19: this has the tendency of counteracting the deposit of sediment at the bottom oI' the tank.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is l. In a fire extinguishing plant having a pair of tanks adapted for the reception of two separate solutions to be delivered to a point without said tanks and there commingled and expelled through a nozzle adapted to be opened and closed to control such delivery, a fluid-operated ejector pump for each tank, a delivery inainleading from tlie delivery end of each pump to said point of' mixing, connections leading' from the liottoms of said tanks to the inlet endsot said pumps, and by-passes leading from the upper ends of' said tanks to the outlet ends of said pumps to afford an escape for the operatimq` fluid when said nozzle is closed and to permit the returnof solution to said tanks irrespective of Whether or not said nozzle is open or closed.

2. ln a lire extinguishing plant having` a pair of tanks adapted for the reception of two separate solut-ions to be delivered to a point without said tanks and there coniiningled and expelled through a nozzle adapted to be opened and closed to control such delivery, a fluid-operated ejector' pump for eaeli tank, a delivery main leading from the delivery end of' each pump to said point ol mixing, connections leading; from the bofioins of said tanks to the inlet ends of said pumps, and lay-passes leading from' the upper ends of said tanks to the outlet ends of lsaid pumps to afford an escape for the operating:r Huid when said nozzle is closed aud to permit the return of solution to said tanks irrespective of whether or not said nozzle is open or closed, and automatically actuated non-return valves in said connectionsadapted to fully open when said nozzle is fully opened and to only partially elose upon fully closing said nozzle.

i 3. In a fire extinguishingr plant having a pair of tanks adapted for the reception of two separa-te solutions to he delivered to a point Without said tanks and there coinmingled and expelled. through a nozzle adapted to be opened and closed to Control such delivery, a fluid-operated ejector pump foreach tank, a delivery main leading from the delivery end of each pump t0 said point of mixing, connections leading.;l from the liettoins oi' said tanks to the inlet ends of' said pumps, and by-passes leading from the upper ends of said tanks to the outlet ends of said pumps to afford an escape for the operating* fluid when said nozzle is closed and to permit tlie return of solution to said tanks irrespective of Whether or not Said nozzle is open or closed, means common to lioth of' said pumps for 'supplying an op Yeratinp` fluid thereto, and non-return valves for each tank, a delivery main leading from the delivery end of eaeh pump to said point of' mixing, connections leading from the liotfoins of said tanks to the inlet ends of said pumps` and liv-passes leading from the upper ends of said tanks to the outlet ends of said pumps to afford an escapefor the operating fluid when said nozzle is closed and fo permit the return of solution to said tanks irrespective of Whether or notsaid nozzle is open or closed, automatically actuated non-return valves in said connections adapted to fullv open when said nozzle fully opened and to only partially close upon Yfully closing said nozzle, means common to looth of said pumps for supplying; an operating1 fluid thereto, and non-return Valves intermediate said common mea-ns and said pumps.

In Witness whereof, I hereunto subscribe my name this 29th day of May A. D. 1925.

A HOWARD EDWIN BEDFORD. 

